Unbiased Variance Estimators in the Parametric Case

Unbiased estimators for the variance are considered in the parametric case. Two methods of finding unbiased estimators are discussed. The first method is designed for one-parameter truncated families of distributions in which the minimum or maximum sample component is a sufficient statistic. The second method of unbiased variance estimation which is is based on unbiased estimators for an integral functional of distribution densities.